The present invention relates to new compounds useful as amphoteric surface active agents, a process for producing same and the use of the compounds. More particularly, the present invention relates to new disubstituted aliphatic carboxylamidoamines of the general formula: ##STR2## wherein R stands for an aliphatic hydrocarbyl group with 7-7 carbon atoms and M for a hydrogen atom or an alkali metal atom, a process for the production of same and detergents and toiletry composition containing the compounds of the general formula (I) as active ingredients.
Hitherto, compounds of the general formula: ##STR3## wherein R' stands for a long chain aliphatic hydrocarbyl group and M' for a hydrogen atom or an alkali metal atom, which are obtained by reacting a straight chain aliphatic carboxylic acid ester with aminoethylethanolamine were known as amphoteric surface active agents of substituted amidoamine type (U.S. Pat. Nos. 3,262,951 and 3,941,817).
Such amphoteric surface active agents are employed as detergents, fiber-treating agents, anti-static agents, toiletry bases and the like. In the case of using surface active agents as bases for shampoo, rinse, liquid facial soap and the like toiletries, such surface active agents are required to have no or little irritating property to skin, eyes and mucous membranes. However, the amphoteric surface active agents of substituted amido-amine type represented by the general formula (II) are not satisfactory in this respect and are thus unsuited for the purpose of bases for toiletries.
As a result of extensive researches made for developing amphoteric surface active agents which are less irritative to skin, eyes and mucous memburanes and thus suitable as bases for toiletries, it has now been found that new compounds of the above general formula (I) are suitable for this purpose and that the new compounds of the general formula (I) can be prepared efficiently by saponifying a reaction product of a 1-hydroxyethyl-2-substituted imidazoline, an alkyl acrylate and water with an alkali hydroxide. The present invention has been accomplished on the basis of the above findings.